A hallmark of alcohol use disorders (AUD) is its heterogeneous genetic and behavioral underpinnings. The advent of next generation sequencing combined with transcriptomics has begun to reveal that not only the underlying gene sequence is important. Indeed, changes in the regulation of key genes (e.g., epigenetic regulation) play a strong role in the predisposition to and development of AUD and associated phenotypes. One potential key epigenetic regulator of these gene networks involved in AUD is the autism susceptibility candidate 2 gene (AUTS2). Recently, variations of AUTS2 have been shown to be associated with a variety of AUD-related behaviors including ethanol (EtOH) consumption and impulsivity. Combined with preliminary data showing that the AUTS2 protein is a critical player in a transcriptional activation complex, this suggests that AUTS2 may play a key role in regulating gene networks underlying AUD. The proposed research tests the hypothesis AUTS2 may contribute to aberrant brain transcriptional networks associated with select AUD pathologies (e.g., EtOH consumption). Aim 1 will identify the core components and chromatin dynamics of AUTS2-chromatin complex in cortical neurons through purification, mass spectrometry as well as AUTS2 association with histone marks and transcriptional activation. Aim 2 examines the role of AUTS2 transcription regulation in the prefrontal cortex of high- and low-EtOH preferring mice. For these studies I will examine differences in the expression, genome-wide occupancy and transcriptional regulation of AUTS2 within the prefrontal cortex of inbred mouse strains that show high (C57BL/6J) and low (DBA/2J) EtOH preference. Aim 3 identifies behavioral and molecular contributions of AUTS2 to AUD using transgenic mice. For this I will generate an Auts2 forebrain-specific conditional knock-out mouse and examine EtOH phenotypes using a behavioral battery including a two-bottle choice test to assess EtOH preference, conditioned place preference for EtOH, and EtOH-induced ataxia on the rotarod. Perhaps the most exciting possibility is that these studies will reveal that AUTS2 may regulate large gene networks involved in AUD thus shedding light on how large-scale disruptions in gene networks lead to the emergence of and predisposition to AUD-phenotypes. By examining how these molecular events map onto AUD, this study will guide future research in devising pharmaceutical interventions for AUD.